Because they're pacing everything out. Nintendo has pretty much at least one first party title coming a month.
March: The Legend of Zelda: Breath of the Wild
March: 1-2 Switch
March: Snipperclips
April: Mario Kart 8 Deluxe
May: Nothing (but has exclusives like Street Fighter, plus big titles like Minecraft)
June: ARMS
July: Splatoon
Then later this year we have, Nintendo published, Fire Emblem Warriors, Super Mario Odyssey, Xenoblade Chronicles 2, and probably some surprises. Plus we have third party games like Sonic Forces.
You're being ridiculously obtuse here. You're ignoring facts and logic to push your narrative.
This is where I wanted to come at. Breath of the Wild was a game that happened to Switch because it was happening to Wii U. It's a crossgen game.
I won't talk about 1-2 Switch for obvious reasons. Same for Snipperclips.
Mario Kart 8 Deluxe ? That's a glorified port with added DLC.
Nothing is nothing, as you said (and come on... Street Fighter II ???)
Which leaves us ARMS and Splatoon 2. ARMS is a game that clearly is meant for Switch and has a justification in developpement time. Even though I'm still waiting on to see for the content itself.
Splatoon 2 exist because Splatoon existed on Wii U. What I mean by that is that it's relying heavily on previous assets and content from the Wii U game, hence making the developpement of this game quite fast. I'm still waiting to have a judgement on if extensive work has been done.
Which leaves us, First party internally developped wise, Mario Odyssey, which has been in the making for 4 years (and seems to, at least, justify such a developpement) and Xenoblade Chronicles 2, which is the real big thing here in term of developpement, considering that it may have been developpement in 2 years and yet feature extensive content
My point with all of that is to question Nintendo's abilities. If you're talking about calendar though, the point still stand. Appealing, original Switch titles for now are in a number of 4.